Psu clementine for mac driver#

The Drosophila gastrointestinal (GI) tract has served as a powerful and genetically accessible model system for the exploration of the biology and age-related decline of regenerative capacity in barrier epithelia ( 4, 8вЂ“ 12). Understanding these qualities and gaining insight into age-related changes in such SSCs are crucial for the development of interventions into a range of chronic inflammatory diseases. SSCs in barrier epithelia are exposed to a unique combination of intrinsic and extrinsic stressors, yet they also exhibit remarkable regenerative potential and resilience. Such rejuvenation can improve regenerative activity in many tissues and bears promise for the development of interventions that promote tissue repair in older patients ( 3, 5, 6). Strikingly, heterochronic parabiosis experiments have demonstrated that SSCs can be rejuvenated by changes in the systemic environment, indicating that systemic factors can over-ride the defects accumulated in these cells.

Psu clementine for mac driver#

The resulting accumulation of molecular damage in organelles, as well as of DNA, lipids, and proteins, has been described as a possible driver of SSC decline, especially in tissues such as the muscle ( 3, 5вЂ“ 9). At the same time, the long-term maintenance of SSCs in a quiescent state means that SSCs are exposed to environmental and intrinsic stressors often for many years before they are needed for a regenerative response.

As the animal ages, for example, systemic stress signals tend to be elevated, resulting in skewed SSC responses to damage ( Figure 1). This susceptibility allows SSCs to appropriately respond to changes in the organism's condition, but it also poses a risk for the long-term health of regenerating tissues. This renders stem cells susceptible to changes in their microenvironment as well as the broader physiological status of the animal, including to its metabolic and inflammatory condition. The precise context-dependent regulation of SSC activity and function is achieved through a combination of cell-intrinsic, local, and systemic regulators, which all impinge on stem cell function and thus on regenerative capacity and structure of the tissue ( 1вЂ“ 4). Such somatic stem cells (SSCs) exist in many tissues in vertebrates, where they have to be carefully controlled to maintain their regenerative potential while preventing deregulation that could lead to dysplasias and neoplasias.Дepending on the needs of each tissue, resident SSC populations are controlled and activated in specific ways: SSCs in the muscle and the upper airways, for example, are often maintained in a quiescent state and only activated after tissue damage, while SSCs in the small intestinal epithelium are always active, providing a continuous stream of progenitor cells that go on to differentiate into the cell types lining the intestinal lumen ( 1вЂ“ 3). Central to this capacity is the availability of a population of cells with sufficient potency to recreate all differentiated cell types needed for tissue function. Most animals harbor an intrinsic capacity to heal and regenerate tissues. SOMATIC STEM CELLS: LOCAL, SYSTEMIC, AND CELL AUTONOMOUS REGULATION